Switch for refrigerating apparatus



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SWITCH FOR REFRIGERATING APPARATUS Albert 0. Grooms, Dayton, Ohio, assignor to General Motors Corporation, Dayton, Ohio, a corporation of Delaware Application October 30, 1944, Serial No. 560,996

3 Claims.

This invention is related in one specic aspect to refrlge'rating apparatus, but more properly to ,controls such as' may be used for refrigerating Iapparatus and countless other applications.

My Patent No. 2,231,532, issued February 11, .5 frame 20 to make the large aperture therein. 1941,' is a typical prewar refrigerator controls. .This plug or disk 26 is provided with a smallA While it was considered simpler and less expensive aperture therein DI'OViding access to the inthan its predecessors there were certain expensive teror f the bellDWS 24. OVer riiiS aperture parts and constructions therein. Some of these there iS bonded the end Of the Capillary tubing expensive parts and constructions are the bellows 23 by Soldering 0r some other suitable method mounting construc'tion and the frame and switch The Opposite @lid 0f this Capillary tubing Ordinarmechanism, The setting of the switch following ily iS pinched oil and sealed by soldering. This manufacture was also a, problem end is ordinarily clamped to the evaporator of the It is an object of my invention to provide an refrigeratins System. Prior to sealing the end improved control which has a durable simple of the capillary tubing, the tubing 28 as well as and. inexpensive be110WS,.f1am3 and tube conthe interior Of the bellOWS 24 S Charged With a struction Y suitable fluid, such as sulphur dioxide or methyl- It is another object of my invention to provide Chloride 2S is Well known in the art.

a simple independent adjustment for both the Between the less of the U-shaped frame opening and closing position, 20 there is provided a block 30 of electrical insulating Essentially these objects are obtained by emmaterial which is held in place by the screws 32 ploying a simple U-shaped frame having a large passing through apertures in the frame and aperture in its yoke which regejvgs the Open end threaded illtO the block. Preferably mOided in of the bellows. The opening in the open end the block are the terminal members 34 and 36 of the benows is closed by a plug containing an 23 which are threaded to receive the terminal screws aperture over which the end of the capillary 0n the upper or outer face of the block. The tubing is placed and soldered, The plug as well inner end of the terminal member 33 has a leaf as the open end of the bellows and the frame Spring member 38 riveted to it. The other end are joined and sealed by a single solder joint. 0f this leaf Spring member 38 is provided with a Ablock of insulating material is fastened between 30 CODtaC Which S lee'eted irl alignment With a the legs of the U and supports a simple switch Contact provided upon the inner end of the termechanism which is connected directly by a minal 34. The terminal 34 is connected by its bellows follower to the bellows. Separate screws terminal screw to one supply Conductor 40 while threaded in the insulating block serve as simple the terminal 36 is connected by its terminal screw adjusting stops which engage the bellows follower to a motor 42 which may be used to drive the to limit its movement in opposite directions to compressor of a' refrigeratnig system. provide a simple independent and inexpensive Soldered or otherwise secured to the bellows opening and closing adjustment for the control. 24 is one end of the bellows follower 44 which Further objects and advantages of the presentv extends toward the leaf spring 38. This bellows inventionwill be apparent from the following 40 follower 44 hasaportion 4S of electrical insulating description, reference being had to the accommaterial which is riveted or otherwise secured panying drawings, wherein a 'preferred form of to the portion 44. This insulating portion 46 is the Present iIiVentiOn iS clearly shown. provided with `a slot which hooks the mid-portion In the drawings: of the leaf spring member 38. The leaf spring Fig. 1 is a view in elevation of a refrigerator 45 member 38 is provided with a small tongue 48 control embodying one form of my invention: which engages a notch (hidden by the spring 38 Fig. 2 is a sectional view taken along the line in Fig. 2) in the slot of the insulating member 2-2 of Fig. 1; 46. to lock this leaf spring member 38 in the slot Fig. 3 is ya sectional view taken along the line in the insulating member 46.

3 3 of Fig. 1; and 50 The metal portion of the bellows follower 44 is Fig. 4 is a sectional view taken along the line provided with a projection 50 shown in Fig. 2, 4-4 of Fig. 1. as being in engagement with the inner end of an Referring now to the drawings, there is shown adjusting stop screw 52 which is threaded in a a refrigerator control with a simple U-shaped threaded aperture 54 extending entirely through frame 20 having in the yoke portion thereof a 55 the insulating block 30. This stop screw is prolarge aperture which receives the rim 22` at the open end of the copper bellows 24. Within the rim 22 there is provided -a plug v26 which may be formed of the disk which is punched out of the 3 vided with a screw-driver slot or other type of head such as Allen head, so that it may be adjusted to change the stopping point of the bellows follower in the Closed position to Vary the open- "ne, point of the switch mechanism. The bellows follower member 44 is provided with letral pro'fcction 56 which is positioned so as to engage the rnlargcd head 53 of an adjusting .ferew'iillthreaded in a threaded aperture extending through the insulating block 38 to its outer face. This screw 60 is likewise provided with a screw slot or Allen, or some other type of head, within the insulating block. This screw 6l) may be turned to changethe stopping p oint of the bellows follower in the' open position of the switch mechanism so as to vary the closing point of the switch.

To cause the .switch to operate with a snap action, the bellows follower portion 44 is provided with apair of notches receiving the 'hardened knife edges provided at the adjacent ends of the toggle links .62 of the toggle link 62 is also provided with a hardened knife edge which is received in a notch provided in a boss 64 formed in the side wall of the frame. The toggle link 64 is likewise provided with a hardened knife edge at its outer end which is received in a notch in the upper end of the spring bar 68. This spring bar 66 at its lower end is provided with a tongue 68 which rides in a slot in the yoke of the-frame 28 at one side of the bellows 24. On either side of the tongue 68 acting against shoulders on the spring bar 86 are compression coil springs and 12 which serve to urge this spring bar 66 upwardly, so that a tongue 14, which is struck out from it is always held against Vthe surface of the cam 16.

This cam 16 has a splined aperture which is fitted upon a splined portion of the rotatable shaft 18.- The shaft 16 extends through a slot 80 in the bellows follower portion 44 and is slidably and rotatably mounted in an aperture provided in the left leg of the frame 20. The cam 16 is provided with a projection 11 for engaging an arm 45 projecting from the vertical portion of the bellows follower 44 to lock the bellows follower andthe switch contacts in the open circuit position in the extreme clockwise position of the cam v16. The cam 16 is held in place by a C-shaped key 82 which extends into a slot provided at the end of the splined portion of the shaft 18. The shaft 18 is provided with an enlarged threaded portion 84 providing a shoulder which -bears against the spring bar 68 as shown in Figs. 1 and 4. This threaded portion 84 is threaded through a flange-threaded aperture provided in the right leg of the frame 28. The shaft 18 is rotated by an adjusting knob 86.

The control is enclosed by a generally U- shaped sheet metal member 88 which serves as a removable case. This member 88 extends over the right leg of the frame and encloses all of the parts within the rectangular space provided by the frame and the insulating block 30.

While I have chosen to illustrate my invention by a refrigerator control having a single set of switch contacts, it is applicable to all sorts of and 64. The outer endl controls whether they operate one or more sets a second of switch contacts or one or more valves.

While the form of embodiment of the invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, as may come within the scope of the claims which follow. y

What is claimed is as follows:

l. A bellows-operated'control comprising a U- shaped metal frame, a block of electrical insulating material extending between the ends of the legs of the U-shaped frame.and fastened thereto, a switch mechanism mounted upon the iti-turned side of the block and having terminals extending through the block to one of the other faces; a metal bellows fastened to the yoke of the frame. a bellows follower operatively connecting said bellows and said switch mechanism, and a range adjusting means mounted upon one of the legs of the U-shaped frame for acting upon the bellows follower to vary the range of the control.

2. A bellows operated control comprising a support, a control device mounted upon said support, a bellows mounted upon said support, a bellows follower extending directly between and connecting said bellows and said control device, a spring means for controlling the movement of the bellows follower, a cam for adjusting the tension of said spring means, said bellows follower having an arm projecting adjacent said cam. said cam having a projection for engaging said arm to lock said bellows follower and said control device in one position of said cam.

3. A bellows-operated control comprising a U- shaped metal frame, a block of electrical insulating material extending between the ends of the legs of the U-shaped frame and fastened thereto, a switch mechanism `mounted upon the inturned side of the block and having terminals extending through the block to one of the other faces, a metal bellows fastened to the yoke of the frame, a bellows follower operatively connecting said bellows and said switch mechanism, bearing means provided in each of the legs of said U-shaped frame, and a common adjustment means mounted upon the bearing means of each of said legs for simultaneously adjusting both the opening and closing of said switch means.

ALBERT O. GROOMS.

REFERENCES CITED The following references are of record in the nie of this patent:

UNITED STATES PATENTS Number Name Date 1,507,591 Frankenberg Sept. 9, 1924 1,791,896 Henning Feb. 1o, 1931 1,988,848 Kuhn Jan. 22, 1935 2,119,317 Dasher May 31, 1938 2,125,627 Fonseca Aug. 2, 1938 2,291,501 Persons v--- July 28, 1942 FOREIGN PATENTS Number Country Date 522.503 Great Britain June 19, 1940 

